The 2025 National Spring Swimming Championships kicked off on Tuesday in Qingdao, east China's Shandong Province, with four gold medals awarded on the opening day.

Zheng Huiyu of Zhejiang Province clinched the women's 200m individual medley title in 2 minutes and 12.18 seconds, edging out her world champion teammate Yu Yiting, who took silver in 2:12.47.

In the women's 100m freestyle, Cheng Yujie of Jiangxi Province secured gold in 53.91 seconds.

"This year's winter training was my best in recent years. I want to use these races as preparation for upcoming competitions and test my limits in the 200m butterfly and 400m freestyle. Staying injury-free is my top priority," said Yu.

On the men's side, Sun Jiajun, who earned 100m butterfly bronze at last year's Paris Olympics, topped the men's 100m fly in 52.08 seconds.

"My focus is on consistent training and incremental progress, and I believe I can perform even better," the Hubei swimmer said.

Shandong's Zhang Zhanshuo dominated the men's 1,500m freestyle in 14:54.06.

The six-day event features multiple Paris 2024 medalists, including Zhang Yufei, Qin Haiyang and Ye Shiwen, as swimmers test form ahead of this year's Chinese National Games.